Lathe



April 24, 1945.

C. A. BICKEL LATHE Filed NOV. 27, 1940 13 Sheets-Sheet l ATM/M575 April1945- c. A. BICKEL 2,374,322

v LATHE Filed Nov. 27, 1940 15 Sheets-Sheet 2 April 24, 1945 m Cll'll.MTEITI C. A. BICKEL LATHE Filed Nov 27, 1940 13 Sheets-Sheet 3 a/rrmmam BY April 24, 1945.

C. A. BICKEL LATHE Filed Nov. 27, 1940 13 Sheets-Sheet 4 MNN A TTOR/VD'SApril 1945- c. A. BICKEL 2,374,322

LATHE Filed Nov. 27, 1940 13 Sheets-Sheet 5 April 1945- c. A. BICKEL2,374,322 I LATHE Filed Nov. 27, 1940 13 Sheets-Sheet 6 lNvENToRCLIFFORD A. BICKEL ATTORNEYS C. A. BICKEL April 24, 1945.

LATHE Filed Nov. 27, 1940 13 Sheets-Sheet 7 mMEH Arm/M515 April 24,1945.

Filed NOV. 27, 1940 V LATHE c. A. BlCKEL 15 Sheets-Sheet 8 m/Mrs LATHEl3 Sheets-Sheet 9 C. A. BICKEL Filed Nov. 27, 1940 April 24, 1945.

C. A. BICKEL April 24, 1945.

LATHE Filed Nov. 27, 1940 13 Sheets-Sheet l0 i AZ'IIIIIIIII/IIIII/I/IIIIIA INVENTOR CLIFFORD A. BICKEL B] W T03-ATTORNEYS C. A. BICKEL April 24, 1945.

LATHE Filed Nov. 27, 1940 13 Sheets-Sheet ll a ma 9 April 24, 1945.

c. A. BICKEL LATHE Filed Nov. 27, 1940 15 Sheets-Sheet 12 INVE/VTORCLIFFORD A. BICAEL $22224, yJMM A rromm April 24, 1945. c A BlcKEL2,374,322

LATHE Filed Nov. 27, 1940 13 Sheets-Sheet l3 INVENTQR CgroRo A. BKMEL.

UMxTM ATTORNEY Patented Apr. 24, 1945 LATHE Clifford A. Bickel, Sidney,Ohio, assignor to The Monarch Machine Tool Company,

Sidney,

Ohio, a corporation of Ohio Application November 27, 1940, Serial No.367,446

17 Claims.

This invention relates to lathes, and in particular to improvements inthe controlling systems associated with the head stock and gear box oflathes.

It is an object of the invention to provide a lathe with an improved andsimplified transmission control for the speed transmission.

It is another object of the invention to provide a lathe in which allspeed adjusting and transmitting shafts, gears and clutches in the headstock and gear box are fully and completely enclosed so as to facilitatelubrication of the movable parts while preventing any undesiredparticles from entering the head stock and/or gear box.

It is a further object of the invention to provide a gear box in whichthere is a separate feed rod and lead screw thread casing means, andmeans to select the drives for the lead screw chasing means and the feedrod, together with novel means of actuating a gear tumbler and selectivegearing associated therewith.

Another object of the invention consists in the provision of a lathehaving a plurality of cone gears and a tumbler gear cooperatingtherewith, in which the axial adjustment of the tumbler gear relative tosaid cone gears may be effected by rotation of a controlling member onthe outside of the lathe.

It is another object of the invention to provide a lathe with cone gearsand a tumbler gear in which the adjustment of the tumbler gear relativeto the cone gears is controlled by a positive locking and unlockingmechanism.

Another object of the invention consists in the provision of a lathe asset forth in the preceding paragraph in which the operation of theunlocking and locking mechanism positively and concomitantly effectsmovement of the tumbler gear away from and toward the cone gearsrespectively.

It is also an object of the invention to provide a lathe with a tumblergear and speed varying cone gears in which the tumbler gear is held inalignment with its respective cone gear by a positive locking mechanismwhich releases the tumbler gear only when it has been fully disengagedfrom its cooperating cone gear.

A still further object of the invention consists in the provision of alathe having a plurality of speed varying cone gears and a tumbler gearadapted selectively to mesh with each cone gear,

controlled so as to allow engagement of the tumbler gear with theselective cone gear only when the latter is in proper alignment with thetumbler gear.

Another object of the invention consists in the provision of a lathewith a tumbler gear and cooperating cone gears in which the lockingoperation of the tumbler gear is effected in two steps so as first tolock the tumbler gear against axial movement and thereupon againstradial movement, whereas the unlocking'of the tumbler gear is eifectedby first releasing the same in radial direction and thereupon in axialdirection.

It is another object to provide a lathe with cone gears and acooperating tumbler gear and a locking mechanism for the latter in whichthe lockin and unlocking of the tumbler gear is effected without causingan undesired torque in the locking mechanism.

A further object consists in the provision of a lathe with a tumblergear and cooperatingcone gears in which the tumbler gear when engagingits respective cone gear occupies a substantially vertical position soas to reduce the lifting component to a minimiun, thereby easing thespeed changing operation. 1

Another object of the invention consists in the provision of a lathehaving a tumbler gear and cooperating cone gears with simplifiedtranslat-l in means for visually indicating the axial move ment andposition of the tumbler gear relative to the cone gears.

It is another object to provide a lathe with a pointermoving in lineardirection forindicating the advance of a feed rod and/or leadscrewassociated with the lathe. I

It is a still further object of the invention to provide a lathe with afeed or speed indicator which moves parallel and in correspondence-tothe movement of a tumbler gear cooperating with cone gears. I

A still further object of the invention consists in the provision of alathe as set forth in the preceding paragraph in which the feed or speedindicator moves over a rectangular feed and thread chart with equalspace for all numbers.

It is also an object to provide a lathe controlling mechanism comprisingtwo cooperating members in which one member may selectively be pushed inaxial direction to exert a rotative movement of the second member or maybe rotated to exert an axial movement of said second member.

Still another object of the invention consists in the provision of alathe in which the tool movement is reversible by ascrew and nuttransmission adapted to convert a pushing movement of the screw into arotative movement of the nut and vice versa.

It is a still further object of the invention to provide a lathe inwhich at least some of the shafts in the gear box are journalled inantifriction bearings of the self-oiling type.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

Figure 1 shows a front view of the lathe according to the invention.

Figure 2 is a section along the line 2--2 of Figure 1. a

Figure 3 is a section along the line 3-3'- of Figure 2.

Figure 4 is a section along the line 44 of Figure 2. a

Figure 4a is a section along the line 4a,4a of Figure 4.

Figure 4b is a skeleton view showing the driving connection between thespindle gearing. and a portion of Figure 4.

Figure 5 is-a-section along the line 5-5of Figure 4.

Figure 6 is asection taken along the line 6-6 of. Figure 4.

Figure '7 is a perspective view showing thelocking and adjustingmechanism for the tumbler gear with regard to the cone gearsin the gearbox.

Figure 8 shows a detail of the locking mechanism of. Figure '7'.

Figure 9 is a sectionthrough a handle associated with the locking andunlocking mechanism for the tumbler gear.

Figure 10 is a side view of the handle shown in Figure 9.

Eigure 11v shows controlling. levers associated with. the: speedselecting: mechanism.

Figure12 shows a chart used in .connectionLwith the spindle speed.selector mechanism and. tumbler adjusting means according to theinvention.

Driven by the spindle in the head stock through the usual end gearing isthe gear system in the gear box 3| which is connected to the side of thebed 32. Mounted on the outside of the gear box 3| is a chart 33 whichcooperates with a pointer 34 for adjusting and selecting the desiredfeed or thread. The pointer 34 is operable by rotation of of the knob35. While the pointer 34 determines the vertical row on the chart, thelevers 36 and 31 arranged on top of the gear box 3| select thehorizontal row on the chart 33.

The gear box 3| furthermore carries on its outside a handle 38 forselecting the drive of the lead Figure 13 shows a view of the linkagesystem in line |4| 4 of I Figure 16.

GENERAL ARRANGEMENT The lathe accordingto the present inventioncomprises a cabinet leg 2| with a rapid transverse drive compartment 22which houses the. rapid transverse drive motor (not shown). The rapidtransverse drive motor drives, by means of a gear transmission, thespindle in. the head stockv 23 whichinits turnis adapted to. rotateawork piece betweenthe centering point 24 and. the centering point 25..The speed gear mechanism in the head stock 23 is controlled by thelevers 26, 21,28 and 29 which are adapted to be set by the operator incorrespondence to the desired speed. 36 designates a computing dial fordetermining thespindle speed when the diameter of. the work piece to bemachined and the surface speed have been determined.

screw 39 or feed rod 40. The speed of the lead screw or feed rod isdetermined by the selection of the gears in the gear box.

The lathe is provided in the usual manner with an apron 41 which is apart of the carriage 41 supporting the cross slide 42 which in its turncarries a swivel 43 and top slide 44. The lever 45 controls thelongitudinal feed while the lever 46 controls the cross feed. Thecarriage 41 is either automatically advanced or retracted by the feedrod or lead screw or may be manually advanced or retracted by operationof the handwheel 48. The motorfor driving the lathe may be connectedwith or disengaged from the gear system in the lathe by operation of oneof the start-stop handles 49.

The handle 5|! serves to-unlock the tumbler gear idler 16- (see Figures4 and '7 for horizontal movement along the cone gears 52 and alsodisengages the tumbler gear from that cone gear with which it happens tobeinmesh. The: horizontal movement of the tumbler is effected byrotation of the knob 35. The position of the handle 53 determineswhether the lead. screw or feed rod is driven in forward or reversedirection. Operation of the lever 54 is adapted to cause closure of theconventional half nuts on the lead screw for engaging the carriage withthe lead screw.

If, instead of the drive by the lead screw, it is desired to drive thecarriage from the feed rod, the lever 45 or 46 is operated depending onwhether longitudinal or cross feed is required. The lead screw reverserod 55 carries a stop collar 56: which, in cooperation with the knurledadjusting nuts 51, is adapted to stop the advancing movement of the toolcarrying the carriage 41.

' GEAR Box' I Arrangement of gear system As previously mentioned, thegear box 3| houses the gear system for determining the speed of the leadscrew and feed rod'and, thereby, oi the feed of the tool supported bythe carriage 41.

Referring to Figures 3 and '7, 58 is the input gear which is keyed tothe input shaft 59 and meshes with one of the quadrant gears in the rearor at the end of the lathe bed. Keyed to or integral with the inputshaft .59 is a gear 60. The shaft 59 is journalled on one end in anantifriction bearing SI of the self-oiling type. while the other end ofthe input shaft 59 is journalled in an anti-friction bearing 62. Thegears 58 and 60 are adapted to mesh with gears 63 and 64 respectively,which form the so-called cluster gear. The gears 63 and 64 are connectedwith each other and keyed to the shaft 65 so as to be slidable as a unitthereon.

When the gears 64, 63 occupy the position s own in Figure 3, the gear 64is in mesh with the gear 68, while shifting movement of the gears 64 and63 toward the right (with regard to Figure 3) causes the gear 64 todisengage the gear 60, while the gear 63 will mesh with the gear 58.

The shaft 65 which is journalled in a self-oiling anti-friction bearing68 and in anti-friction bearings 61, 68 has rigidly connected orintegral therewith a gear 69. Mounted in the gear box 3| and enclosingthe gear 89 is a sleeve I which has an opening II through a large partof its length. Slidably mounted on and shiftable about the sleeve I8 isa fork shaped arm or tumbler I2 carrying a pin I3. The pin I3 is held inits position by a set screw I4 and supports an anti-friction bearing I5on which is journalled the tumbler gear idler l6.

. The tumbler gear idler I6 meshes with the gear 69 and is adaptedselectively to be engaged with and disengaged from the cone gears 52supported by and keyed to the cone gear shaft 18.

Thecone gear shaft I8 is journalled in antifriction bearings I9 and 80.In addition to the cone gears 52, the cone gear shaft I8 has also keyedthereon three gears 8|, 82 and 83, of which the gears BI and 83continuously mesh with the free running clutch gear 84 and the freerunning clutch gear 85 respectively, while the gear 82 is adapted tomesh with the clutch gear 86. While the clutch gears 84 and 85 arefreely rotatable about the cone clutch shaft 81 journalled inantifriction bearings 88 and 89, they are held in their position by anyconvenient means and are provided with jaws 90, 9| respectively, adaptedto engage the jaws 92 or 93 of the clutch gear 86, depending on whetherthe clutch gear 86 is shifted on the shaft 8'! toward the left or theright with regard to Figure 3. The clutch gear 86 is keyed to the shaft81 by means of a key 94 so that rotation of the shaft 8'! will cause theclutch gear 86 to rotate.

As will be obvious from the above, the provision of the clutch gear 86and the free running clutch gears 84 and 85 afford three differentspeeds depending on whether the clutch gear 80 is in the position ofFigure 3 or in engagement with either clutch gear 84 or clutch gear 85.In the first instance the drive of the cone gear shaft I8 is transmittedthrough gear 82 and clutch gear 86 directly to the shaft 81. When thejaws 90 and 92 of the clutch gears 84 and 86 engage each other, thedrive of the cone gear shaft 18 follows the gear 8!, the free runningclutch gear 84 and the clutch gear 86 to the shaft 87. When the jaws 93and 9| of the gears 86 and 85 engage each other, the drive of the conegear shaft 18 is transmitted through gears 83, 85 and 86 to the shaft81.

The cone clutch shaft 8'! is supported at its outer end by a bushing 95in the feed rod plate or housing cover 96. Slidably mounted on and keyedto the shaft 8'! between the bearing 89 and the bushing 95 is a slipgear 91 which is movable so as selectively to engage a gear 98 keyed orotherwise connected to the lead screw 39 or a gear I00 keyed orconnected in any convenient manner to the feed rod 40. The end of thelead screw 39 adjacent the lead screw gear 98 is journalled inanti-friction bearings I02 spaced from each other by a bushing I03. Apacking I04 prevents leakage of oil toward the outside. The speed of thefeed rod or lead screw is determined as follows:

As previously mentioned, the gear 58, keyed to the input shaft 59, isdriven by a motor through a gear train so that, depending on theposition of the cluster gear 63, 64, the rotated movement of the inputshaft 59 is conveyed to the shaft 65 either through gear 63 or 64.Supposing that the tumbler gear idler I8 is in engagement with one ofthe cone gears 52, the rotated movement of the shaft 65 is conveyed tothe respective cone gear 52 through the gear 69 and the tumbler gearidler 16.

If the clutch gear 86 occupies th position shown in Figure 3, the coneshaft 18 drives through the gear 82, the clutch gear 86 which in itsturn drives the slip gear 91 by means of the shaft 81. Since, in theposition shown in Figure 3, the slip gear 91 engages the feed'rod gearI00, rotation of the slip gear 9! drives the feed rod 40. If it isintended to drive the lead screw 39 instead of the feed rod'40, the slipgear 91 is to be brought into engagement with the lead screw gear 98. Incase the jaws 92 of the clutch gear 86 engage the jaws 90 of the freerunning clutch gear 84, the cone gear shaft I8 drives through gear BIand the gear 84 which imparts Shifting movement of cluster gears 63, 64

The side faces of the gear 64 are engaged by a fork. I05 (see Figures 4and 7), which is slidably mounted on a bar I86 with its sleeve portionI0 5a and positions the gears 63 and 64 relative to the gears 58 and 60.The bar I06 is rigidly connected at its ends to the gear box casing andhas two notches I0! and I08 therein adapted selectively to be engaged bya detent plunger I09 for retaining the cluster gear 63, 64 in thedesired position.

The detent plunger I09 is continuously urged into engagement with one ofthe notches I01, I08 by means of a spring IIO, the thrust of which isadjustable by a set screw I I I.

The fork I05 for shifting the cluster gear 63, 64 is moved in one or theother direction by operation of the handle 36 which is pinned to theshaft H2 (see Figure 4 and 5). The shaft H2 is shiftably mounted in thehousing cover II 3 and rigidly connected in any convenient manner, forinstance. by a screw I I 4 with a fork I I 5. The fork II5 engages a p nH6 which is rigidly connected with the sleeve I05a of the fork I05.Consequently, shifting movement of the handle 36 causes a partialrotation of the shaft I I2 which in its turn shifts the fork II5, whichlatter converts, by its engagement with pin II6, the rotative movementof the shaft II2 into a longitudinal sliding movement of the fork I85,I05a so as to cause the gear '64 of the cluster gear to me h with thegear 60 or to cause engagement of the gear 63, pertaining to the clustergear, with the ear 58.

The two possible positions of the handle 39 corresponding to the twopossible positions of combined with the vertical row ind cated by thepointer 34, as will be fully described later. Shiftina movement ofclutch gear 86 gula'r groove in the gear box casing. In corre-.-spondence towthe three possible positions of the clutch gearSB, theslide bar H8 is provided with three notches II9, I20 and I2I, milled inone of the faces of the slide bar. The notches I I9, I20 and I2I areselectively adapted to be engaged by a detent assembly I22. The detentassembly I22 is substantially similar to the detent assembly comprisingthe parts I09, H and III, for'maintaining the position of the slide barI06.

Rigidly connected to the slide bar II 8 is a block I23 with a pin I24.The pin I24 is enga ed by a fork I25 which is rigidly connected to theshaft I26 journalled in the housing cover I l 3. The outward end of theshaft I26 has rigidly con nected. thereto the handle 31. Consequently,shifting movement of the handle 31' causes a shifting movement of theshaft I26 which, due to the fork I25 engaging the pin I24, converts therotative movement of the shaft I26 into a longitudinal sliding movementof the pin' I 24', thereby causing the bar II8, rigidly connected withthe block I23 which latter carries the pin I24, to move in one of itsthree possible positions in which it is held by means of the detentassembly I22.

The three different positions of the handle 31 are marked C, D and E(Figure 11) and correspond to the three different speedsin accordancewith the three positions of clutch gear 86. The positions C, D and Eserve for selecting, in cooperation with the handle 36, the horizontalrow on the chart 33, which will be combined with the vertical row on thechart selected by the pointer 34, The actual selection of the horizontalrows will be described in detail later.

Shifting movement of slip gear 97 The side faces of the slip gear 91 areengaged by the forked block I 21' (see Figures 4 and 6), which swivelsin the lever I28 pinned or otherwise keyed to the shaft I29. The shaftI29 is .iournalled in bushings I30 which are carried by a tube I3Ipressed into the gearbox casing, The outer end of the shaft I29 haskeyed thereon, for instance by means of a screw I32, the hand 38.

Also keyed to the shaft I29, for instance by a pin I33. is a detentsegment I34 adapted to be engaged by a detent plunger I35 which iscontinuously urged into engagement with, the segment I34 by means of aspring I36, the thrust of which, if desired, may be varied in a mannerknown per se by means of a set screw (not shown in the drawings).

Shifting operation of the handle 38 in one or the other directiontherefore causes a partial rotation of theshaft I29 and the lever I28connected thereto which, due to the swivel connection of the forkedblock I21 with the lever I28, shifts the slip gear 91 in one or theother direction so as to bring the same into engagement either withthe-feed screw gear I00 or lead screw gear 98.

Ada'ustment of tumbler gear idler 76 The control of the tumbler andtumbler gear idler has always proved difficult in a totall enclosed gearbox, which fact is responsible for" the large opening inmost lathe feedand thread gear boxes. However the mechanism which will presently bedescribed provides a means of controlling these gear box elementswithout the necessity of any open slots or bores.

As will be seen from Figures 2 and 7,the tumacvaaaz bler- 12 has rigidlyconnected therewith a. bell studi I131 which is adapted to cooperate wasthe cam surfaces I38 and I39 of the cam plates I40 and MI. The camsurfaces I38 and I39 are shaped in correspondence with the diameters ofthe-cone gears so that the tumbler gear idler 16 is'always in engagementwith its respective cone gear when the ball stud I31 is clamped betweenthe cam surfaces I38 and I39.

Thecam plates I40 and I4I are slidably supported by any convenient meansand adapted to-be spaced from or moved toward each other. The cam plateI40 has a protruding portion I42, which is adapted to cooperate with arecess I43 in the rack slide I44 carrying racks I4 5on each end.The'ra'ck slide I44 is slidably mounted on the .cam plate I40 but isrigidly connected with the cam plate I4I, for instance by means of ascrew I46. When the ball stud I31 is in its clamped position, theprotruding portion I 42 is spaced from the adjacent end wall portion ofthe recess I43.

Meshing with the racks I45 are pinions I41 integral with or rigidlyconnected to the pinion shaft H9. The pinion shaft I48 has keyed theretothe handle 50. The bottom portion of the cam plate M0 is provided withnotches I49 adapted to be engaged by a correspondingly shaped jaw I50supported by and connected to the selector shoe I5I'. The selector shoeI5I which engages the side faces of the tumbler 12' is slidably mountedon the tubular slide I52, having pins' I53: projecting through a slotI54 (see Figure 8) in the greater part of the length of the slide I52and connected to the rack rod I55. The tubular slide I52 is heldstationar in the gear box casing by any convenient means, for instanceby screws I56. Furthermore, the ends of the tubular slide I52 are'plugged by plugs I51.

The rack rod I55 engages the teeth of an idler I58 through another slotI59 in the tubular slide I52. The idler I58 which is rotatably mountedabout the stud I60, connected to and supported by the gear box casing,engages the pinion gear I BI which is keyed or otherwise rigidlyconnected to the shaft I82 and, thereby, to the'knob'35.

Connected with the selector shoe I5'I' is the pointer 34 which ismovable beneath and along a glass cover I64. This pointer, as previouslymentioned, moves relative to the columns on the I chart 33 which, ifdesired, may be'mounted under a separate'glass cover or under a glasscover covering both the pointer and the chart. In the latter instance,the pointer34 may extend across the entire chart.

To facilitate the shifting and locking of the pinion shaft I48, alocking device is provided between the handle 50 and the pinion shaftI49 (see Figures-9 and 10). This locking device comprises a swivel blockI keyed to the outer end of thepinion shaft by means of a key I66 andconnected to the handle 50 by means of a swivel pin I61, so that thehandle 50 maybe swung about the axis of the pin I61. The swivel blockI65 has an indentation I38 in its upper surface which is adapted to beengaged by a detent plunger I69 continuously urged against the swive1block I65 by a spring I10- which is located in a recess I1I of thehandle 50.

a hardened'plate I13 with a slot I14 therein for engaging the head I15of the screw I16 threaded into the gear box casing. The plate I13 isconnected with the handle 50 by means of screws I11. By pulling the knobof the handle 50 away Y The handle 50 furthermore comprises a recess I12to receive from the screw I16, the locking plate I13 disengages the headI15 so that the handle 50 is free to be rotated transverse to the axisof the swivel pin I61 for rotating the pinion shaft I48.

Supposing that the tumbler gear idler 16 is in engagement with one ofthe cone gears 52 and that it is now desired to change the speed of thefeed rod or lead screw by means of shifting the tumbler gear idler 16,the operator first actuates the handle 50 by pulling the same away fromthe screw I16 so as to disengage the plate I13 from the head I15. Nowthe handle 50 is rotated transverse to the axis of the swivel pin I61 soas to rotate the pinion shaft I48. Rotation of the pinion shaft I48 and,thereby, of the pinions I41 causes the rack slide I44 to move so thatthe cam plate I4I connected thereto moves away from the ball stud I31.When the rack slide I44 has moved by such a distance that the endsurface I18 of the recess I43 engages the protruding portion I42 of thecam plate I40, further movement of the rack slide I 44 also moves thecam plate I in the same direction as the cam plate I4I so that the ballstud I31 will be shifted by the movement of the cam plate I40 in thedirection of said movement. The shifting movement of the ball stud I31connected to the tumbler 12 rotates the latter so as to disengage thetumbler gear idler 16 from its respective cone gear. It should, however,be noted that the movement of the tumbler 12 in the direction of thelongitudinal axis of the shaft 65 is prevented by the engagement of thejaw I with the respective notch I49 until the rack slide I44 has reachedits outermost position in which the jaw I50 is disengaged from itsrespective notch I49 in the rack slide I44. This outermost position ofthe rack slide I44 maybe indicated by a stop on the gear box casingagainst which the handle 50 may abut. Now the knob 35 is rotated,thereby rotating the gears I6| and I58, which latter meshes with therack rod I and causes the. same to move the selector shoe I5I in one orthe other direction.

Inasmuch as the pointer 34 is connected to the selector shoe I5I, theposition of the latter, relative to the columns on the chart 33,indicates the position of the tumbler gear idler 16 relative to the conegears. As soon as the tumbler gear 16 has been brought into alignmentwith the desired cone gear 52, the knob 35 is released, whilethe handle50 is actuated so as to rotate the pinions I41 in opposite direction forreturning the cam shape of the cam surfaces I38 and I39, The adjustingoperation of the tumbler gear 16 and the speed change elfected therebyis now completed, and to prevent accidental movement of the pinions I41,the handle 50 is shifted toward the screw I16 until the plate I13engages the screw head I15, thereby locking the handle 50 in itsposition.

It will be noted that even an accidental partial movement of the rackslide I44 will not cause any change in the positionpf the tumbler gear16, since it still will be locked, due to the engagement of the jaw I50with its adjacent notch I49 in the rack slide I44.

As will be clear from the above, the tumbler gear shifting mechanismaccording to the present invention" allows shifting movement of thetumbler gear without having a slot or an open bore in the gear box. Afurther advantage of the tumbler gear. shifting mechanism according tothe invention consists in that a positive locking and unlocking,mechanism is provided for locking and unlocking the tumbler gear. Thelocking notches I49, cooperating with the jaw I50, serve the furtherpurpose ofproperly aligning the tumbler gear 16 with its respective conegear 52. Unless the tumbler gear 16 is in proper alignment with itsrespective cone gear, the jaw I50 is in misalignment with the adjacentlocking notch I49, and prevents the return of the rack slide I44 and camplate I4I into, its locking position; in other words, the tumbler gear16 cannot be brought into engagement with the desired cone gear, unlessit has reached its proper position.

It will further be clear from the above description that a positivedisengagement of the tumbler gear from its respective cone gear iseffected concomitantly with the unlocking of the ball stud I31 and,unless the tumbler gear has been fully disengagedfrom its respectivecone gear, the jaw I50- will still be in engagement with its adjacentlocking notch I49, thereby preventing movement of the tumbler 12 in thedirectionof the axis of theshaft 65. I

In this connection it may also be mentioned that, due to the fact thatthe pinions I41, which are rigidly connected to the pinion shaft I48,engage With' a rack at eachtendof the rack'slide I44, no torque can beimparted to the rack slide I44 by the shifting movement of the pinionshaft I48. 7 Consequently, also no undesired torque will be imparted tothe tumbler 12 during its shifting operation.

Due to the fact that the shifting mechanism for the tumbler 12 issubdivided into amechanism for locking and unlocking the tumbler 12 andfor spacing the same from the cone gears, and intoamechanism'for movingthe tumbler 12 in the direction of the shaft 65, it has been madepossible to translate themovement of the selector shoe I5I into ahorizontal movement of a pointer indicating the movementof thetumblergear in the directionof the 'shaft65. As a result thereof, thepreviously and commonly used circular dials for positioning the tumblergear idler 15 with respect to the cone gears could be replacedby arectangular chart with even spaces for each number.

It should also be noted that according to the arrangement shown inFigure 2, the tumbler gear idler 16 is so arranged that whenever itengages one of the cone gears 52, the plane common to and through thecenters of the tumbler and tumbler gear idler is always substantiallyvertical. 'The advantage of this arrangement consists in that thelifting componentfor disengaging the tumbler idlergear 16 from itsrespective cone gear 52 is a minimum, thereby easing the operation ofthe knob'for' effecting gagement.

Adjustment 0 feed ifor lead scrwho-r feed rod The threads tobe chased bythe lead screw or feeds obtainable by: the feed rod according toavailable. speed gears in the lathe are plotted on the chart (Figure 13)which is subdivided into a plurality of squares arranged in-horizontalandvertical rows and each comprising two figures. The upper figurecorresponds to the said disenthread which may be chased by' the leadscrew and the lower figure in the samesquare corresponds to the feed.per revolution of the spindle obtainable by the feed rod. Thehorizontal rows are marked AC-AD-AE--BC-BD-BE, and indicate the relativepositions of the levers 36 and 31 toward each other. These levers,asprevious- 1ymentioned under the heading Shifting movementofclusterlgears 63,64 and Shifting movement of clutch gear :86 determinethe speeds corresponding to the position of the cluster'gear '63, -64.and the clutch gear :86. The relative positions of the levers 35 and 3!determine the horizontal row of the chart 33, for instance, in-Fi u-rellthe handle 36 points to B, while the handle 31. points to D. Thehorizontal row on the chart 33 corresponds to the relative positionofthe handles 36' and 31 for the horizontal row marked BD. T

In order to shift the tumbler gear so that the gear systemwill cause thelead screw or feed rod to yield the desired thread or feed in theselected horizontal' row, the knob 35 is rotated so that thepointer uwill be inalignment with the desired thread or feed value in theselected horizontal row. In other words, while the position of thehandles 35 and 31 determines the horizontal r ow on'the chart 33, thepointer 34 determines the vertical row which contains the desired threador speed value in the horizontal row. The actual shif-tlng operation ofthe tumbler gear-16 which deter-mines the movement-of the pointer 34 hasbeen described underthe heading Adjustment of tumbler gear idler 16.

pI-IrsnSrocn" Start-stop mechanismjor spindle drive- "Referring' toFigure 17, the pulley .II9 which is driven by the motor in the rapidtransverse drive compartment 22 .is freely ,rotatably journalled in theanti-friction bearings I81] carried by aprojection .IBJla at the end ofthe head stdck 23. Connected with pulley =Il9,'for instance by screwsII8I, is a driving ring I 82 which is toothed on its inside and engages'a' correspondingly toothed clutch disc Ii8.3. .O'neside of the clutchdisc I83, is-adapted to be engaged by a clutch member I84 which is keyedto the hollow shaft I85, for instance by a hollow dog pointset screwI86. I

The clutch member 184 has a splined portion I81 which meshes with alcorrespondinly shaped splined portion of a second clutch member I88adapted to engage the other sideof the clutch disc I83. Threaded on orotherwise connected to the'clutchmember I84 is a ring I89,.withears I90(only oneear shown) which are connected by links I9I and I92 with a yokeI93 which is threaded upon .a shaft I94 and secured thereon b the locknut I95. The shaft I94 isjournalled in bushings I96 lanyd lll'l andextends throughout the entire length of the hollow shaft I 85. Each link(I M has a surface I 9 la adapted to press against the annular surface I88a of the clutch member I88 so as to move the latter toward the clutchmember I84, thereby pressing the (clutch disc 1%3- between the clutchmembers I84 and I88 ,If this is effected, the rotationof thepillley,;I;'I.9 is conveyed through the clutch disc I83 and the clutchmember all to the :hollow shaft I85.;,j';l;he hollowshaft J85 drives agear train whichwill bedesciibedlatern V 1 v The end of. the shaft I84opposite the lock nut I35 is keyed. for instance by a pin I98, to a discI99 and clutch'sleeve 200. The clutch sleeve 200 base circular recess2III engagedby'blooks 202 (Figure '14) which are swiveled in the clutchfork 203.

Operation of the clutch for-k 203 causes the clutch sleeve 200 to movein one .directionor the other. If the clutchlsleeve 201! moves towardthe left, with'regardto Figure 1'1, the shaft "4 moves the yoke L93toward the left which, by means of the links Ill, spaces the linksurface IBIa from the surface 8a .of the clutch member I88, which latterthen slides on the splined I portion 1181 of the clutch member I84toward the outside, thereby interrupting the driving connection betweenthe pulley I19 and the hollow shaft I85. If, on the other hand, theclutch sleeve 2" is moved toward the right, with regard to Fig- .ure1.7, the links :I9I press against the clutch member I 88 and. cause. thelatter frictionally to engage the clutch disc I83, thereby establishingdriving connection between the pulley I1! and the hollow shaft I85.

The clutch fork 203 is keyed by means of key 2M (Figure 14) to a shaft205 which has keyed thereto a sleeve 206 with a ,iorked arm 2"comprising a pm 208. Pivotally connected to the forkedarm 201, by meansof the pin 208, is a link 2053 (Figure 13), the other end of which ispin otallyconnected by means of .pin 22:) with a similarly fork shapedarm 2H. The sleeve ortion 2.12 of the arm 2-H (Figure 15) is keyed bykey 12 I3 to a shaft 2I4, which is 'journalled in the gear box casingand inbushings 21 5, spacing the shaft 2I4 from the sleeve .2I6surrounding the shaft 1214. The sleeve 2I'6 is rotatably mounted in thegearbox casing. Leakage along the shaft :2I4 and the sleeve 2.16 is'prevented'by packings 2II and 2I-:8 held in :place by anyconvenientmeans.

The shaft "2 has Skeyed thereto, for instance by a pin'flfl, a segment22. (Figure 2) The segment 2220 meshes with a cylindrical rack 221 whichis integral with the cylindrical rack 222 (Figure 4). The cylindricalracks HI and 222 are slid-ably mounted m ths gearbox casing. Thecylindrical rack 2'22 meshes with a gear segment 223 which is keyed, forinstance by pin124,to the shaft 225 (Figure :6), which is rotatablymounted in the gearbox casing.

'Key'ed to the lower portion of the shaft 215,101 instance by a pin 226,is a bevel gear 221 meshing with a similar bevel gear 228 keyed to theshaftfls. The shaft! has also keyed thereon the handle 49 (Figure 1').Shifting movementoi the handle 19in one -or the other direction causes apartial rotation of the shaft 22! -0Flgure 6) which, by means of thebevel gears m and 22! and the shaft 225, causes theygear segment 223connected thereto to swing in one or the other direction. a I

Swinging movement of thelsegment 223 causes a longitudinal movement :oftheraok 222 (Figure 4) so that the rock 1221 GF igure 2) causes aswingin movement of the gear segment 22.

meshing therewith. The swinging movement of I the ,gear segment 220causes a partial rotation of the shaft 2: and, thereby, also or the forkshaped arm 2| I (Figures 13 and 15). The movement of the/arm 2.44 isconveyed through the link 1209 to the .arm'ztll (Figure 14) which iskeyed :to the shaft'jfli and, thereby, causes a shifting movement .ofthe clutch fork 1202 keyod totheshaft205. v

The shifting movement of the clutch rorkil: causes the clutchsleeveiflll to move intone or the other direction, thereby causing theshaft !94 and the yoke I93 connected therewith to effect or interruptthe driving connection between the pulley !19 and the hollow shaft !85which, as previously mentioned, drives the spindle of the lathe througha gear train.

Spindle speed control The speed of the spindle shaft 236v is controlledby a gear system provided in the head stock 23. This gear systemcomprises a gear 23! which is keyed to the hollow shaft !85 adapted tobe driven by the motor in they rapid transverse drive compartment 22 andthe pulley I19 drivingly connected therewith.

The gear 23! meshes with the idler gear 232 having jaws 233 adapted tobe engaged by corresponding jaws of the clutch sleeve 234. The clutchsleeve 234 is keyed to the shaft 235 but slidably mounted thereon so aseither to engage the jaws 233 of the gear 232 or the jaws'236 of theidler gear 231 which meshes with a gear 238 also keyed to the hollowshaft I85.

The shaft I95 is journalled in' anti-friction bearings 239, while theshaft 235 is journalled in anti-friction bearings 249. Keyed to theshaft 235 are gears 24! and 242 respectively meshing with gears 243 and244. The gears 243 and 244 are idler gears on the shaft 245, which isjournalled in anti-friction bearings 246 and has a splined portion onwhich is slidably mounted a clutch sleeve 241 adapted selectively to beengaged with the jaws 249 pertaining to the gear 243 or with the jaws249 pertaining to the gear 244. The shaft 245 has a second splinedportion on which is slidably mounted the correspondingly splined clutchsleeve 259, which is adapted selectively to be engaged with the clutchjaws 25E pertaining to the idler gear 252 or the clutch jaws 253pertaining to the gear 254.-

The gear 254 is keyed to a sleeve 255 having integral therewith a gear256 meshing with an idler gear 251 comprising jaw clutches 258. The

spindle shaft 239 has a splined portion slidably engaging acorrespondingly splined clutch sleeve 259, which is adapted selectivelyto engage the jaw clutches 258 pertaining to the gear 251 or the jawclutches 269 pertaining to the gear 26! which meshes with the gear 254.The gear 26! is integral with a sleeve 262 rotatable about the spindleshaft 239 and having keyed thereto a gear 263 meshing with the gear 252.The spindle shaft 239, which is journalled in antifriction bearings 264and 265, has keyed thereto two gears 266 and 266a, which are adaptedselectively to drive a train of end or quadrant gears which aredrivingly connected with the gears in the gear box as previouslymentioned under Arrangement of gear system.

The clutch sleeves 234, 241, 259 and 259 in the head stock are shiftedinto one or the other position by means of the levers 26, 21, 28 and 29respectively. To this end the lever 26 (Figures 1 and 16) is keyed, forinstance by pin 261, to a shaft 266 which is journalled in bushings 269and 219 spaced from each other by a sleeve 21! surrounding the shaft 268and spaced from the latter. The sleeve 215 is rotatably mounted in thehead stock casing and is surrounded at'its outer end by a packing 212 toprevent leakage along the outer surface of the sleeve 21!, while leakagealong the shaft 268 is prevented by a packing 213.

The shaft 268 has keyed thereto, for instance by a pin 214, a sleeve 215pivotally connected with an arm 216 (Figure 13) which, in its turn, ispivotally connected by a pivot 211 with a lug 218 of the sleeve portion219 (Figure 13) whichis integral with the clutch fork 289 and rotatablymounted on the shaft 28!. The clutch fork 289 has swiveled thereinswivel members 262 which engage the annular recess 283 (Figure 17) ofthe clutch sleeve 241.

Consequently, when the lever 26 is shifted in one or the otherdirection, the shifting movement ,of the lever 26 causes a partialrotation of the shaft 268 and, therefore, also of the sleeve 214, whichpartial rotation is conveyed, by means of the arm 216, to the sleeveportion 219 of the clutch fork 289, so as to swing the latter in one orthe otherdirecti'on, thereby causing the clutch sleeve 241 to engageeither the jaws 248 pertaining to the gear 243; or the jaws 249pertaining to the gear 244, thereby positioning the respective gearsaccording to the desired speed.

To lock the lever 26 in its respective position, it is provided with adetent plunger 284 continuously urged by means of a spring 285 intoengagement with one of three detents or looking members 286 carried bythe head stock casing; only one of said detent members 286 being shownin the drawings. The adjustment of the spring 285 is determined by thesetting of the screw 281.

As will be seen from Figure 16, the lever 26 can be shifted only afterit has been pulled away from the respective detent member'286 byshifting the handle 26 about the pivot 288 so that the detent plunger284 slides over the end of the detent member 296. In order to preventthe detent plunger 284 from leaving its recess in the lever 26 when thelatter is shifted about the pivot 288, a retaining screw 289 is providedin the handle 26 which engages a slot 299 in the detent plunger 284,thereby preventing the same from leaving its recess. After the lever 26'has been shifted into its desired position it is shifted back about thepivot 288 so that the plunger 234 engages another detent member 286 andis held thereby in its desired position.

The lever 21 (Figures 1 and 16) is, similar to the lever 26, shiftableabout a pivot 29! and is.

keyed by a ring 292 to the sleeve 21! which has also keyed thereon asleeve 293 with a lug 294 pivotally connected by a pivot 295 with a link296 (Figure 13) which, in its turn, is pivotally connected by pivot 291with a-lug 298 of a sleeve 299 which is keyed by a pin 399 to the shaft28!. Also keyed to the shaft 28!, by means of a pin 39!, is a sleeveportion 392 integral with the clutch fork 393.

The clutch fork 393 has swiveled therein swivel members 394, whichengage the annular recess 395 of the clutch sleeve 234 (Figure 17).Therefore, shifting movement of the lever 21 in one or the otherdirection causes a partial rotation of the sleeve 21! and, thereby, ofthe sleeve 293 keyed thereto which, by means of the arm 296 and thesleeve 299 keyed to the shaft 28!, causes a shifting movement of theclutch fork 393, likewise keyed to the shaft 28!, Depending on whetherthe clutch fork 393 is shifted in one or the other direction, the clutchsleeve 234wi1l engage either the clutch jaws 233 pertaining to the gear232 or the jaws 236 pertaining to the gear 231, thereby placing the gearsystem in the head stock into the position corresponding to the desiredspindle

